One week last year, Jonathan Ledgard was talking with White House officials about how drones could deliver cargo to remote Africa. The next week, he was in a remote African village, telling elders how drones could change their lives.

He heard the same fears from both audiences: Will the drones crash into houses? Will they spy on people? Will they attack people?

The human armpit has a lot to offer bacteria. It's moist, it's warm, and it's usually dark.

But when the bacteria show up, they can make a stink. That's because when some kinds of bacteria encounter sweat they produce smelly compounds, transforming the armpit from a neutral oasis to the mothership of body odor. And one group of bacteria is to blame for the stink, researchers say.

The Obama administration is pledging that the U.S. will reduce greenhouse gas emissions by 26 percent to 28 percent of 2005 levels over the next 10 years. The new target was submitted today to the U.N. Framework Convention on Climate Change.

NPR's Michel Martin led two challenging conversations about race this week, focusing on fearful perceptions of African-American men and how these fears play out in people's everyday lives. Guests including author and Georgetown University Law Professor Paul Butler examined the research and the complicated emotions behind this fear.

"When you're in an elevator or walking behind somebody and you feel like you have to perform to make them feel safe, it's like apologizing for your existence," says Butler.